The present invention relates generally to gas fired infrared heaters, and more particularly to a gas fired infrared radiant tube heating system which utilizes plural burner assemblies mounted in a common housing along with a single gas valve and a single control circuit module, the flame from each of the plural burner assemblies being forced through an associated radiant tube heat exchanger.
Gas fired infrared radiant tube heaters have been developed in many forms. They vary by input, length, size of the radiant tube heat exchanger, also called an radiant pipe or emitter tube, as well as by other factors. Typical prior art patents are U.S. Pat. No. 3,394,886, U.S. Pat. No. 3,416,512, U.S. Pat. No. 5,211,331, EP 0 070 360, GB 2,189,314 A, CA 1,011,314, and GB 2,274,703. These devices are utilized for heating people within a enclosed spaces, for example the space within a building, such as an auditorium, factory building, aircraft hanger, house of worship, vehicle service facility, warehouse, or public hall. Infrared heating has particular application in heating spaces where there are high ceilings. Thus, infrared heating heats from the floor up, greatly reducing heat stratification to the ceiling. Thus there is no need to employ down-draft fans to recover heat lost at the ceiling. In addition, as air temperatures are lower at the ceiling, transmission losses to the outside air are far lower. Infrared heating also has particular application in buildings which have high air change rates, for example aircraft hangers and vehicle service facilities. When the doors to these facilities are opened, most of the warm air is lost to the outside. To reestablish people comfort, if heated with warm air, the interior air volume has to be reheated and driven down from the ceilings. However, if heated with radiant heat, as the floor and surrounding objects are large heat reservoirs, warmth is drawn up and out of the floor, achieving people comfort quickly while larger building spaces may still be at a minimum air temperature. While an infrared heater has particular application for heating people within a fully enclosed space within a building, these heaters have other applications. Thus they may be used to heat people within partially enclosed spaces such as open walkways, grandstands, and tee boxes at golf driving ranges.
There has been an increasing need for heaters with greater thermal output. An infrared radiant tube heater""s output capacity is generally limited by the type and size of the tubular heat exchanger connected to it. Thus, there is an effective maximum fueling rate for a radiant pipe of a given diameter and length. A major drawback to the continuing trend of higher thermal output from a single burner assembly is that the heat distribution is generally poor. This is because as fueling rates are increased for radiant pipes of a given diameter and length, hot spots will be created. Unless the building in which such a heater is installed is of sufficient height, there will likely be uncomfortable conditions below the hottest portion of the heat exchanger. The easiest way to solve this problem is to install more heating systems at a lower thermal output thus eliminating the large hot spot from a larger heater and providing more even distribution of the infrared heat. This method causes installation costs to be higher than that of an installation with the higher thermal output burners, as each burner system is provided with its own valve and control circuit module.
It is an object of the present invention to provide a gas fired infrared heater which provides higher thermal outputs without the heat distribution and installation cost problems of the currently available infrared heaters.
More particularly, it is an object of the present invention to provide a gas fired infrared radiant tube heating system for heating an enclosed space, said system including two or more radiant tube heat exchangers, a common burner housing which is connected to the two or more radiant tube heat exchangers, two or more separate burner assemblies carried by the common burner housing, there being one burner assembly interconnected with each of the radiant tube heat exchangers, each burner assembly being capable of firing an associated radiant tube heat exchanger, and a single gas delivery system mounted within the burner housing and connected to a source of combustible gas, the single gas delivery system being interconnected with the two or more separate burner assemblies.
It is a further object of the present invention to provide a system of the type set forth above with a single gas valve assembly.
It is yet another object of the present invention to provide a system of the type set forth above with a single manifold, the manifold having a single inlet and two or more outlets, and wherein each of the burner assemblies is connected to one of the outlets of the single manifold.
It is another object of the present invention to provide a system of the type set forth above with a single control circuit module mounted within the burner housing, the control circuit module monitoring ignition and operation of each of the burner assemblies, and controlling the single gas delivery system.
In accordance with this invention, the problems associated with the prior art and other problems are solved by providing a burner housing capable of igniting and supervising a plurality of gas flames. Thus, the invention consists of a burner housing with two or more burner ports, each of which can be connected to a typical radiant tube heat exchanger assembly. The burner housing will contain a single gas valve, single control circuit module, and multiple blower proving switchs. In addition, in positive pressure configurations it will also have a single air fan. A manifold from the gas valve will distribute the gas to the multiple burner assemblies. The foregoing design will provide a higher thermal output without the heat distribution and installation cost problems of the currently available infrared heaters.
The foregoing objects and advantages of this invention will be more fully understood after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which preferred forms of this invention are illustrated.